First Evidence of Middle Triassic Basic Magmatism in the Southwestern Part of the Dzhugdzhur-Stanovoi Superterrane (Ilikan Terrane)

摘要

U-Pb ID-TIMS zircon analyses of the Dzhigda gabbro-gabbrodiorite Massif (Ilikan block in the southwestern part of the Dzhugdzhur-Stanovoi superterrane) have been carried out. The results demonstrate that the formation of the massif at 244 +/- 5 Ma corresponds to one of the stages of formation of the Selenga-Vitim volcano-plutonic belt. The latter stretches along the southeastern margin of the North Asian Craton along its border with the Mongol-Okhotsk fold belt. This indicates that the Selenga-Vitim volcano-plutonic belt along with granitoids and volcanics comprises Permian-Triassic massifs and that this belt is superimposed onto structures of not only the Selenga-Stanovoi terrane but also the Dzhugdzhur-Stanovoi terrane.